Solution:

Of course, it is impossible. Into the second room should have gone the 2nd guest, because the 13th guest was waiting in room number 1

Solution:

Shop till you drop

Solution:

Six.

There are only five colors, so six socks guarantee that two will be the same color.

Solution:

Queue (remove the last four letters – the pronunciation is the same)

Solution:

A Stamp

Solution:

6 (the number of letters in the month august)

January : 7 letters
February: 8 letters
March : 5 letters
April : 5 letters
May : 3 letters
June : 4 letters
July : 4 letters

Solution:

Summary

Solution:

Short

(shorter - er = short)

Solution:

Professor Frink said: 'I shall be hanged!' If he was lying, he would be hanged. But that's what the Frink was saying. So he speaks the truth. But if he speaks the truth, he would be beheaded, so then he was not speaking the truth. So it is impossible for the judge to determine wether the person speaks the truth or not. So therefore the judge cannot determine the penalty and sets him free.

Solution:

Once upon a time.